Hendry on climate change

David Hendry weighs in on climate change, citing me out of context, but otherwise in his usual sound way.

18 replies on “Hendry on climate change”

I scanned through this and printed it for further perusal.

It seems an excellent summary. Nowhere could I see anything to disagree with.

I was struck by this statement: “For unclear reasons, this evidence seems insufficient to persuade nay sayers”. I am not sure if the reasons are unclear. Ideological/ political differences (sometimes very narrow ones) between contending parties, and the differences between media debates and scientific debates seem to me to be hampering (even totally obstructing) progress.

It is also probably pointless to await the “perfect” decision as to what to do next. Continually kicking for touch is not a winning strategy. Wrong or mistaken decisions can be changed. We are at a point where the worst thing is to do nothing.

It’s a pretty interesting paper, if a little sweeping and general. The citation of Prof Tol is indeed a bit unfortunate when one looks at the succeeding sentences in the source.
I’d agree with Toby that it’s unlikely a lack of ‘clarity’ in the evidence that dissuades the ‘nay sayers’. I’ve noticed (as I’m sure many have) a consistent and predictable pattern: people I know who don’t buy into AGW are invariably a tad right-wing and come from wealthy families (obviously the causality would be difficult to untangle). Surprisingly, I’ve found that people I know in the oil industry (mostly traders/risk people) are far less likely to deny AGW than people I know in banking/funds.
Richard, if you have the time I’d be very interested to know your views on analyses like this one by Beenstock. I attended a lecture he gave in London a while back and wasn’t really convinced. But I am curious to know if the methodology was reasonable? (my understanding of econometrics is limited)

This passage had me rolling in the aisles:

“…to convince the ‘establishment’, Barry Marshall drank Helicobacter pylori to demonstrate that they caused stomach ulcers, followed by a dose of antibiotics to show he had identified the cure. That episode, humorously recounted in Marshall (2005), stresses a key attribute of the scientific process, namely that blockages and even previously undiscovered fraud are often relatively temporary, as the same human forces that create them also motivate others to overturn invalid claims.”

I wonder does this author realise the supreme irony of this statement’s very irrational thought process which he uses to defend the scientific method. As in:

“Criminals always get caught. This is stressed by an anecdote of a criminal who got caught.”

His other great chestnut:
“scientific knowledge is real: from an endless list, it is obvious that electric lights work, computers calculate, planes fly, and scanners can detect cancers. These have become efficient technologies because of scientific understanding”

No. All these have become efficient technologies because of trial-and-error. Trial-and-error is notable for its complete absence of predictive power, and hence is utterly irrelevent to the debate on climate science.

In fact, it is singuarly difficult to find an area of human endeavour in which innovation was the result of (as opposed to the impetus for) scientific theory. There are cases of it, but as a percentage of total human endeavour it is sufficiently rare as to be a consistent with pure chance.


Trial and error, in the sense of making conjectures and testing them, is vital in science. But to say that theory has no influence is a total over-simplification.

When first discovered, quantum mechanics (in the late 1920s) seemed the most arcane and counter-intuitive of sciences. As Richard Feynmann said “It is a myth that few people understand relativity. But nobody understands quantum mechanics”. Yet, by 1950, it had produced the transistor, arguably among the inventions with the greatest social impact of all time. Schockley, Bardeen and Brattain knew what they were looking for and where to look because of quantum theory.

Maxwell’s Equations probably seemed of little note when JCM first wrote them up. Yet within a short while, electromagnetic theory had produced the wireless, and set the scene for modern physics. And technology influences theory. Peter Galison’s “Einstein’s clocks, Poincare’s Maps” showed how the need to measure time accurately influenced a great physicist and mathematician.

The relevance to climate science is that science is a reliable form of knowledge, and its predictions are usually correct. When they are not, we move either into “saving the theory” by an adjustment, or changing the paradigm.


I looked at the Beenstock paper and found this (rather unfalttering) critique on the climate blog of “Eli Rabett”, which is a pseudonym of a Professor of Chemistry (I think) and AGW proponent.


Beenstock and his co-author are a bit beyond my pay grade in time series analysis, but I would always think it risky to pass judgement on a physically observed phenomenon using purely mathematical methods. I remember seeing Galileo’s data set, and if he had used regression analysis, he would never have found the Law of the Pendulum. I work with materials scientists sometimes and we try to cross-validate our results (physical and statistical). So Beenstock et al may not be wrong, just incomplete.

@ toby,

I’m no physicists, but I do make the point above that if you look hard enough for cases in which “theory got it right” you will find them.

Of course, if you look hard enough for cases in which “astrology got it right” you will find them too.

What’s relevant is the number of cases in which “theory got it right” in comparison to the number of cases in which “theory got it wrong”, if we want to talk about predictive power.

Otherwise it’s like me saying in a pub, “eating large portions of food and not exercising will tend to make you obese”

And you say, “oh, I do know…I know this guy who eats like a horse and never lifts a finger, and he’s skinny as a rail…”

Of course, scientists don’t document their failures as well as their successes.

Ribbit, you’re not just wrong, you’re sweeping statement is not even wrong and you’ve equated the scientific method with anecdote. It takes some gall to shamelessly hold the opinions you have posted here considering the staggering level of ignorance you’re displaying.

Do you really think no one at all thought of electric light bulbs until, say, Edison had a eureka moment and then people randomly stabbed at it until someone worked it out? Because that’s what your notion of trial and error implies Your knowledge of history is as bad as your understanding of science.

Ever heard of Provenance? Let’s take radio. Hertz didn’t just wake up one day and say, “let’s see if I can generate radio waves”, his ideas were based on what had gone before – the work of Newton (who split white light with a prism), through Young, Huygens, Faraday, Maxwell to Hertz and then beyond. “Lack of predictive power” my hole!

What level of conceit must one have to shamelessly state opinions about matters far outside one’s core sphere of competence?


Frankly, I did not have to look very hard to find cases where “theory got it right”. The fact that you were unable to enumerate a single contrary case speaks volumes.

If you step back and look at science, you see a set of disciplines that study the world empriically throught a set of fairly well-defined procedures.
It is subject to human error and weakness, but its powers of self-correction are enormous. Science is easily the most succesful collective human endeavour of all time, bar none.

Melansian cargo cults build aeroplanes, and I suppose after “trial and error”, one of them might even fly. By your definition, they are doing science.

@ toby,

I don’t think it speaks volumes that I didn’t mention an example of ‘theory getting it wrong’. If you must have an example, cold fusion stands out in my mind as a costly, complete failure. Another might be the devestating effect of monocultivation and pesticides on the biosphere. Remember these products and practices were recently trumpeted by scientists as the great solution to population problems. Now some forward thinkers are coming around to the notion that a biologically sustainable human population might be much lower…oops, what do we do with the remaining 5 billion?

But I do agree that there is a use to empiricism and – contrary to what you might think – I have a very positive opinion of science as a set of disciplines that study the world.

But when a particular method becomes accepted as dogma – and this is certainly the case with science today – we have to step back before we start leaving undue levels of sacrifice at its alter.

Logically, because empiricism is based on observation, and the human capacity to observe is necessarly finite, in an infinite universe there are an infinite number of things which cannot be studied empirically.

Thus, the problem is not science per se, but the fact that scientists are so unwilling to accept how little they know (literally, next to nothing!). I hear scientists say “ACC is real…90% sure” there are even some who say “ACC is bogus…90%”. But what I don’t here, and what you rarely hear is “we really don’t know, and we may never know.” Because of course, that’s not good for getting funding.

On your assertion that science is easily the most succesful collective human endeavour of all time, I would strongly disagree. First of all, I don’t feel we should view science as an endeavour, but rather as a means of achieving certain endeavours. And I personally would give that accolade to monotheist, organised religion, which created an early blueprint for multiple pillar, complex social structures, interstate cooperation and – ironically – science.

@ dealga,

I’m not going to answer people who call me ignorant, shameless and refer to their ‘holes’. Life is too short for those kinds of acrimonious exchanges.

Cold fusion was bad science. Two scientists were forced into premature public declaration by a grant-hungry University. But their experiment failed the reproducibility test very quickly and the bubble burst within a year. It could be claimed as an shining example of science’s self-correction.

[There are still come mysteries about this incident. See Michsel Brooks’ book “13 things we don’t understand”]

To quote an example against myself, the worst dereliction of scientific principles in history was the acceptance of eugenics and “racial science” for many years, long after it could have been shown to fail by any decent empirical test. Eugenics was (and is) kept going by a human failing for bias that science corrects, sometimes too slowly. It should have been challenged much sooner. But to eliminate excresences like eugenics, science is our best hope.

If I was you, I would argue that AGW is like eugenics. But you will have a hard job convincing me!!:))

“Some scientists say … ACC IS bogus”. I can think of less than a half-dozen. The vast majority of climate scientists accept AGW: AGW is the accepted paradigm that the data is continuing to confirm. The last 13 months have the highest succession of warm months (measured by global averages) since records began. Arctic Ice extent and volume is descending to its lowest summer level ever. Sea level rise is continuing to be confirmed. CO2 is still increasing in the atmosphere. Where is the contrary data to test AGW? Scientists in every discipline will continute to accept a paradigm, even while subjecting it to continuous testing, until a strong body of contrary evidence appears that cannot be assimilated into the theory.

If you read the denialist websites, you will find a rearguard action of nit-picking the papers published by the AGW proponents. Most of it a pure imitation of “Gotcha!” journalism. Only a handful of “skeptic” scientists continue to publish and continue to be refuted. While some of these have been useful challenges, many have not, and even continue to be quoted as gospel.

AGW is no more “dogma” than evolution is a “dogma” among biologists. Do not mistake a “debate” in the media or on blogs for a scientific debate.

Religion vs science is not a debate I would care to get into. Religion has always been with us, science has been around for only a few hundred years. The fact that humanity has made more substantial progress in the centuries since science appeared than in the thousands of years of predominant religious sensibility is good enough for me.


I was going to mention eugenics, you know, but then I stopped myself. Some mates of mine invented a rule for pub debate that the first person who brings up Hitler or the nazis automatically loses the debate.

Sort of a smoking ban for debates. 😉

It is way off topic, but you can argue eugenics without invoking Hitler.

Eugenics was intellectually respectable throughout western society for many years since it was originally conceived by Francis Galton, Darwin’s nephew and pioneer of statistics. It was actually put into practice in the many US states and Sweden by sterilizing poor and lower class women on grounds of “low IQ” and “imbecility”. This was not the same as Hitler’s death camps, but it was bad enough.

In fact, eugenics has not entirely died out, and it lives on in racial IQ stereotyping. If Hitler had not brought it into such deep disrepute, it would probably be much stonger today.

One case, that of a women called Carrie Buck, reached the US Supreme Court in 1927, where the great liberal Justice Oliver Wendell Holmes delivered judgement AGAINST her sterilization, ending with the trenchant phrase “Three generations of imbeciles is enough”. By no modern definition was Carrie Buck and her forebears “imbeciles”.

Carrie Buck was “white trash”. Her young daughter was also covertly sterilized. If you get hold of Stephen Jay Gould’s collection “The Flamingo’s Smile”, he has an essay on the Buck case and its background.

Maybe, I am shooting myself in the foot here! 🙂

Aagh. Error in last post. Holmes delivered judgement FOR sterilization. The vote on the court was 8-1 in favour.

Wow, Toby, I am impressed by your knowledge of eugenics-related issues. And here was me thinking old Adolf had the monopoly on that stuff. I will get Gould’s collection and read it.

Thanks for the reference.

Oh, and as for Dealga’s nasty rhetorical comment on the invention of the light bulb, I just can’t resist a retort:

“Do you really think no one at all thought of electric light bulbs until, say, Edison had a eureka moment and then people randomly stabbed at it until someone worked it out”

That is, in fact, exactly what happened. The passage of electic current was originally conceived in the study of electrolysis, pioneered by Banks and Humphreys in 1800 – 1805. That this created an incandescent effect was quite a discovery by chance. (Edison was a relative latecomer to the game).

Electrolysis, in turn, owes its discovery to the work of the great tinkerer Alexander Volta, from whose seminal letter to Banks we learn that:

“In prosecuting his experiments on the electricity produced by the
mere contact of different metals, or of other conducting bodies the
learned Professor was gradually led to the construction of an apparatus,
which in its effects seems to bear a great resemblance to the
Leyden phial, or rather to an electric battery weakly charged…”


What description could better accord with my conception of “trial-and-error”-ism? How many hair-brained devices did Volta think of, which didn’t produce interesting results, and for which he never sent a seminal letter to Banks? We shall never know, of course.

What useful comparison could possibly be made between the method that underpins this invention and, say, the methods by which the UNIPCC proposes to convince us we should all move to the high ground and build wind turbines?

Ribbit, I didn’t call you ‘ignorant’ in the terms you have chosen to interpret to mount some kind of moral high ground (where you don’t answer someone who calls you, then do).

I referred to your ‘ignorance’, in that you clearly displayed that you have little or no knowledge of the provenance of scientific learning that clearly guides all discovery. Provenance is the rule, not the exception, even for ‘accidental’ discoveries, which still only happen as a result of the work that has gone before (not at all the stab in the dark ‘trial and error’ you described).

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